Yokai Watch 1 for Nintendo Switch is a direct port from the 3DS version with the same file structure and files so a translation port should be possible, only problem I see is there is many text files to sort though and some additional ones to translate.

The archive yw1_a.fa can be unpacked in Karamaru and the text files *_ja.cfg.bin can be open and edited freely Kuriimu, a new problem arises is the newer files seem to have combined both male and female files together so it's hard to tell which is supposed to go where without knowing Japanese for example ev01_0010_m_en.cfg.bin & ev01_0010_f_en.cfg.bin has 19 entries while the new file ev01_0010_ja.cfg.bin has 33 entries.

Haven't checked the image files but I'm assuming it can be edited but priority should be on the in game dialogue.